Alarm system



United States Patent Ofilice 3,318,328 Patented May 9, 1967 3,318,328ALARM SYSTEM Kenneth J. Schrader, Tulsa, Okla, assignor to CombustionEngineering, Inc, New York, N.Y., a corporation of Delaware Filed May26, 1965, Ser. No. 458,936 7 Claims. (Cl. 137557) The present inventionrelates to those systems developed to monitor a plurality of separateconditions by indicating a predetermined change in any one of theconditions. The invention also includes the feature of controllingfactors by the system, the factors having established the conditions.

In the many industrial processes there are a number of operativeconditions which it is desired to monitor. The conditions may go througha predetermined change or completely deteriorate. The changes, completeor partial, should be annunciated in order for supervisory personnel tobe promptly informed. Remedial action by supervisory personnel may thenproceed in a systematic manner. Also, it may be desired that a controlac tion be automatically taken by the monitor system. It may beimportant that the first of a number of the monitored conditions beisolated so the supervisory personnel will have specific information towhich it may react in correcting the condition change.

An object of the present invention is to annunciate which of the numberof the monitored conditions underwent a predetermined change.

Another object is to positively isolate the annunciation of the firstmonitored condition which changed to resolve which of the conditionschanged its predetermined amount.

The present invention contemplates a fluid-pressure manifold connectedin parallel to a series of valves, each valve being capable of ventingthe manifold to a predetermined pressure level. Each valve is maintainedin a closed position by a fluid pressure which is generated from thecondition being monitored by that valve. When this fluid pressuregenerated by the monitored condition reduces to a predetermined level,the valve will be simultaneously actuated by the fluid pressure inannunciating the change while venting the manifold in order topositively prevent the remaining valves being actuated by changes intheir respective conditions. Additionally, the manifold is arranged toactuate any additional annunciation and/or control mechanisms of theprocess required for correction or safety purposes.

Other objects, advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention with specific reference to the accompanying drawings, inwhich:

FIG. 1 is a schematic representation of a complete alarm system in whichthe invention is embodied;

FIG. 2 is a sectioned elevation of one of the valves of FIG. 1 whichresponds to one of the monitored conditions; and

FIG. 3 is the valve of FIG. 2 positioned to annunciate while venting themanifold to render the other valves inoperative.

GENERAL SYSTEM DESCRIPTION In FIG. 1 a plan view of panel board 1 hasbeen illustrated. Valves 2, 3 and 4 are mounted behind this panel boardto extend their annunciating structure from the face of the board. Eachvalve is indicated as responsive to a condition to be monitored. When aparticular one of the conditions changes a predetermined amount, thevalve associated with the condition protrudes a piston from the face ofthe panel board where it can be readily viewed. The specificannunciation on the front of the board can take various forms. Thepiston can be linked to a number of devices to give visualmanifestations.

The valves 2, 3 and 4 are connected in parallel to a manifold conduit 5.The arrangement of the manifold and valves is made so as to vent conduit5 when any one of the valves annu-nciates its condition change. It isthis venting which provides a positive isolation of the first valve toannunicate. In this sense, isolation specifically means that theremaining valves are deprived of this source of fluid power from conduit5 which is required to annun-ciate. Therefore, the first condition to beann'unciated locks the system positively to prevent subsequentannunciation of the other conditions which may subsequently change.Supervisory personnel will then know which of the conditions was thefirst to fail, and remedial action can then be taken systematically.

BASIC POWER SUPPLY The fluid pressure supply for conduit 5 is normallygenerated by compressing air, or gas of some sort. This source of poweris received by the system through conduit 6. From conduit 6, the supplypressure fluid is routed through three-way valve 7, conduit 8,restrictive device 9, and into manifold conduit 5. The pressure inconduit 5 is then maintained until vented through one of the valves 2, 3or 4.

Mani-fold conduit 5 is also connected to diaphragm operator 10. Operator10 positions valve 7 alternately to two positions. As shown in FIG. 1,the pressure of conduit 5 on the top of the diaphragm maintains thevalve 7 in its first position to connect supply conduit 6 to conduit 8.

OPERATOR 10-THREE-WAY VALVE 7 Control valves 15, 16 and 17 are connectedto conduit 8 for actuation when one of the monitored conditions shutsdown the process. It would be possible to connect these shut-in valvesdirectly to manifold 5 so they would be actuated when the manifold 5 isvented. However, in one practical sense, the flow from the air supplyinto manifold 5 must be restricted so manifold 5 can be quickly ventedthrough any of the valves 2, 3 or 4. This delicate balance between theamount of power fluid restricted into manifold 5 and the amount ventedthrough one of the valves 2, 3 and 4 is isolated from the problem ofactuating shut-in valves 15, 16 and 17 by restrictive device 9 connectedbetween conduit 8 and conduit 5. The venting of conduit 8 can then fallprimarily on three-Way valve 7 as actuated by operator 10.

Operator 10 is responsive to pressure in conduit 5 as was explainedsupra. When this conduit 5 pressure decreases to a predetermined value,valve 7 is thrown to its opposite position from the that shown in FIG. 1and conduit 8 is vented, actuating shut-in valves 15, 16 and 17.

It is also possible to annunciate from the pressure in conduit 8. Alight 18 is indicated as connected to conduit 8 for annunciation at someremote location, signaling that the shut-in valves have been taken totheir shut-in positions by the venting of conduit 8.

RESTRICTIVE DEVICE 9 The basic control of the fluid pressure supply ofconduit 6 into manifold conduit 5 is regulated by setting valve 20 inrestrictive device 9. Spring-loaded check valve 21 Will not permitpassage of fluid from conduit 8 to conduit 5. All of the flow must bethrough the seat of valve 20, this being set manually.

When conduit 8 is vented through valve 7, springloaded check valve 21will permit evacuation of manifold conduit 5 through restrictive device9. This is an extra START-UP PROVISION After one of the monitoredconditions has caused the manifold conduit 5 to be vented, the systemmust be eventually placed in the condition indicated in FIG. 1 fornormal operation. After any required remedial measures have been taken,manifolds 8 and 5 may be repressured from conduit 6 through conduit 22which bypasses valve 7. Manually operated valve 23 is placed in conduit22 'for this purpose. Once conduits 5 and 8 are pressured from thesupply in conduit 6, operator will be repositioned to that illustratedin FIG. 1 and the process will function normally until there is anotherpredetermined change in one of the monitored conditions.

MONITOR VALVES FIG. 2 shows valve 2 as illustrative of the valves 2, 3:and 4. To embody the invention, the valve is formed of two simple bodystructures 25 and 26 which are clamped together to form diaphragm cavity27.

Clamped between body housing structures 25 and 26 is a diaphragm 28which isolates port 29 from port 30 while effectively covering one endof cylinder 31 formed in body housing portion 25.

In FIG. 2 diaphragm member 28 is shown as pressed against the internalopening of cylinder 31 so as to seal cylinder 31 against entry of fluidpressure from port 30 which is connected to manifold conduit 5. Withdiaphragm 28 positioned as in FIG. 2, piston 32 .can be pushed backagainst diaphragm 28 and will remain in that position. The outer end ofpiston 32 is then substantially flush with the end of housing portion'25 which is extended through panel 1.

When the pressure from the monitored condition, introduced into port 29,reduces to a predetermined magnitude, diaphragm 28 is pushed backagainst port 29 in housing 26 as shown in FIG. 3. A pressure frommanifold conduit through port 30 then acts upon the inner end of piston32 and pushes piston 32 up against shoulder 33. The outer. end of piston32 is then exposed in the annunciating position and passage 34 in piston32 vents the fluid pressure from manifold conduit 5. Therefore, valve 2simultaneously annunciates the change in the condition that is monitoredwhile venting manifold 5 to positively prevent subsequent change in theremaining conditions from being annunciated on the panel board.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set .forth,together with other advantages which are obvious and which are inherentto the apparatus.

Iit will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombina-tions. Thisis contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that allmatterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

The present invention having been described, what is claimed is:

which the valve retains the pressure of the supply within the manifoldand a second position in which the valve simultaneously vents themanifold pressure to atmosphere and anriunciates the second position,

and a conduit connected to each valve and receiving a fluid pressuregenerated by a separate normal monitored condition of a process whichfluid pressure will hold the valve in its first position, the valvebeing moved to its second position when the monitored condition changesa predetermined amount from normal.

2. The system of claim 1 including,

a control valve regulating at least one of the monitored conditionsconnected to the manifold so as to be actuated when any monitor valve ismoved to its second position.

3. The system of claim 1 in which,

each monitor valve is connected to the manifold and arranged so as toannunciate its second position only if it is the first of the monitorvalves to reach its second position.

4. The system of claim 3 in which,

a restrictive device is connected between the supply and the manifold,the restriction being sized to enable any one monitor valve toeffectively vent the manifold in its second position within apredetermined period of time.

5. The system of claim 3 in which,

a two-position valve is connected between the restriction device and thesupply to alternately and selectively vent the manifold and connect themanifold to supply,

and means connected to place the valve in its alternate positions inresponse to the pressure in the manifold.

6. The system of claim 5 including,

a by-pass conduit around the two-position valve of claim 5,

and a manually controlled two-position valve in the by-pass with whichthe manifold can be initially pressured from the supply and place thevalve of claim 5 in position to connect the manifold to supply.

7. A valve for use in the system of claim 1, including,

a casing having two parts forming a cavity when the two parts arejoined,

a diaphragm dividing the cavity into two sections,

a cylinder in a first of the casing part-s extending into the cavity toform a seat for closure by the diaphragm,

an opening into the second of the casing parts to receive the fluidpressure generated by a separate normal monitored condition of a processand move the diaphragm into sealing engagement with the cylinder seat,

an opening into the first of the casing parts to receive the pressure ofthe supply,

and a piston in the cylinder which is movable into an annunciatingposition by the supply pressure when the condition pres-sure decreasesto a value below the supply pressure and the supply pressure moves thediaphragm away from the cylinder seat.

References Cited by the Examiner UNITED STATES PATENTS 2,635,631 4/1953Seefluth et al. 251-61 X 3,140,726 7/1964 Arenhold 137510 X 3,228,3001/1966 Potts et al. 137-557 X M. CARY NELSON, Primary Examiner.

1. AN ALARM SYSTEM INCLUDING, A FLUID PRESSURE MANIFOLD CONDUIT, ASUPPLY OF FLUID PRESSURE CONNECTED TO THE MANIFOLD TO NORMALLY MAINTAINTHE MANIFOLD PRESSURIZED AND IN AN INOPERATIVE CONDITION, A PLURALITY OFMONITOR VALVES CONNECTED IN PARALLEL TO THE MANIFOLD, EACH VALVE HAVINGA FIRST POSITION IN WHICH THE VALVE RETAINS THE PRESSURE OF THE SUPPLYWITHIN THE MANIFOLD AND A SECOND POSITION IN WHICH THE VALVESIMULTANEOUSLY VENTS THE MANIFOLD PRESSURE TO ATMOSPHERE AND ANNUNCIATESTHE SECOND POSITION, AND A CONDUIT CONNECTED TO EACH VALVE AND RECEIVINGA FLUID PRESSURE GENERATED BY A SEPARATE NORMAL MONITORED CONDITION OF APROCESS WHICH FLUID PRESSURE WILL HOLD THE VALVE IN ITS FIRST POSITION,THE VALVE BEING MOVED TO ITS SECOND POSITION WHEN THE MONITOREDCONDITION CHANGES A PREDETERMINED AMOUNT FROM NORMAL.